It is known to provide a circular knitting machine with a positive yarn feeding apparatus including endless drive tapes which engage a plurality of yarn feeding wheels driven at a predetermined rate in accordance with the operating speed of the knitting machine. The knitting yarns are guided between the tapes and the individual yarn feeding wheels so that the yarns are positively fed to the knitting stations as the endless drive tape is driven.
It is also known to provide a circular knitting machine with a storage type yarn feeding apparatus in which a predetermined quantity of yarn is maintained in storage by winding a suitable number of wraps on a feeding drum so that the yarn is constantly fed under a certain low degree of tension, according to the yarn feeding requirements of the knitting machine. In accordance with this arrangement, it is possible to provide yarn feeding during high speed operation of the knitting machine, and to also prevent any broken yarn end from being knit into the fabric when the yarn being fed is broken.
Recently, it has been the common practice to produce plain knit fabrics that have three or four feed repeat patterns on circular Jacquard machines. In most cases, these plain knit fabrics are of the type which involve no variation in the rate of yarn feeding, such as Milano rib and ponte de Roma. Knitting of these types of plain fabrics may be carried out by employing the aforesaid tape type positive yarn feeding apparatus or the storage type yarn feeding apparatus.
However, in the case of Jacquard pattern knitting in which varying rates of yarn feeding are required at adjacent knitting stations, it has been impossible to employ the tape type positive yarn feeding apparatus or the storage type yarn feeding apparatus because the varying yarn feeding rates required cannot be accomplished by these types of yarn feeding apparatus. Furthermore, for the purpose of pattern changing, it is necessary to relocate the yarn feeding apparatus each time a pattern change is required. In conjunction therewith, it is also necessary to arrange the space required for installation of the yarn feeding apparatuses. This is a very troublesome and time-consuming operation for an operator when pattern changes are required.